3rd redo of installing the super six manifolds....help with gaskets

mvh said
I don't understand how you could *not* have a small leak at the heat riser flap shaft

When they're in good condition, they don't leak.

it has a very loose clearance

After years and years, yes. When in-spec, no.

and there is no bushing.

Yes, there is—and when the heat control valve rebuild kits were still available, they came with new bushings along with the new shaft, new flapper, new counterweight, thermostatic spring, anti-rattle spring, and all the other bits and pieces.

It had to have leaked from the factory.

Nope.